The United States is not determined to halt Iran from getting a bomb and this week’s IAEA report granted Israel even more legitimacy to strike Iran on its own, former minister Tzachi Hanegbi said on Saturday.

Hanegbi, a former MK, minister and ex-chairman of the Knesset’s Foreign Affairs and Defense Committee, said that Israel is not bluffing and that “if there is no credible threat of military action, then there is no other way to convince the Iranians of halting their nuclear enrichment program.” An IAEA report published earlier this week stated that Iran increased its uranium enrichment capacity by 30% in recent months.

Without the Americans, Israel would have no choice but to attack on its own, Hanegbi said at an event in the northern town of Kiryat Motzkin. “The American threat is the most genuine threat there is,” he continued. “American capabilities, the might this superpower possesses… worry the Iranians much more than Israel does.”

Hanegbi was skeptical that the Obama administration would indeed employ military force to halt Iran’s nuclear program. He said that various White House statements — like one made on Friday that it is President Barack Obama’s “firm commitment that we must prevent Iran from acquiring a nuclear weapon” — were amorphous and general.

“In practice, I don’t see this phrase being translated into a more concrete intent. That may be the main reason why the Iranians belittle this threat, protest it, show contempt for it,” Hanegbi said.

For the US, which survived under the threat of thousands of Soviet and Chinese nuclear missiles for decades, he noted, the idea of five Iranian nuclear bombs was not as worrying as for Israel.

“The US really doesn’t have any wish to pay the price of a confrontation between Israel and Iran, should such a thing occur. Otherwise it would have initiated such a confrontation to begin with, without waiting for us.”